Non-isothermal degradation kinetics of virgin linear low density polyethylene (LLDPE) and biodegradable polymer blends

The thermal degradation kinetics of several polymers, including biodegradable blends were investigated in non-isothermal thermogravimetry using several analytical methods. Virgin linear low density polyethylene (LLDPE) and LLDPE blends with polystarch-N (PSN), a prodegradant starch additive material used in 20 and 40 wt%., were investigated to determine the degradation behaviour of such materials in pyrolysis conditions. The results were compared to those obtained with virgin low (LDPE) and high density polyethylene (HDPE). An analytical solution model was also developed to assess the two degradation steps of the biodegradable blends which enabled the assessment of the apparent activation energy (E_a) of each material in the blend on its own based on the initial and final degradation temperatures. It was observed that the thermal behaviour and E_a value didn’t change significantly with the increase of biodegradable prodegradant, which shows that biodegradable blends can be treated with similar conditions regardless of the content of the biodegradable masterbatch present in the blend.